Assembly for protecting a vehicle occupant's head from an impact

Abstract

An assembly ( 10 ) for use in a vehicle comprises a webbing guide ( 30 ) for guiding movement of seat belt webbing ( 14 ) in the vehicle and a fastener ( 70 ) for mounting the webbing guide ( 30 ) in position in the vehicle. The fastener ( 70 ) has a head portion ( 76 ). The assembly ( 10 ) further has a resilient cover member ( 80 ) that includes a cover portion ( 82 ) covering the head portion ( 76 ) of the fastener ( 70 ) and at least a portion ( 32 ) of the webbing guide ( 30 ). The resilient cover member ( 80 ) further includes a first rib portion ( 100 ) projecting from the cover portion ( 82 ) toward the head portion ( 76 ) of the fastener ( 70 ) and a second rib portion ( 110 ) projecting from the cover portion ( 82 ) toward the webbing guide ( 30 ). The first and second rib portions ( 100, 110 ) are resiliently crushable to absorb energy in response to an impact of a vehicle occupant's head against the cover portion ( 82 ).

Having described the invention, we claim:  
     
       1. An assembly for use in a vehicle, said assembly comprising: 
       a webbing guide for guiding movement of seat belt webbing in the vehicle;  
       a fastener for mounting said webbing guide in position in the vehicle, said fastener including a head portion and a longitudinal axis; and  
       a resilient cover including a cover portion covering said head portion of said fastener and at least a portion of said webbing guide,  
       said resilient cover further including a first rib portion projecting from said cover portion toward said head portion of said fastener and a second rib portion projecting from said cover portion toward said webbing guide, said first and second rib portions being resiliently crushable to absorb energy in response to an impact of a vehicle occupant's head against said cover portion, and  
       said resilient cover further including first and second rib extensions which extend from said second rib portion, said first and second rib extensions being spaced apart from each other about the longitudinal axis of said fastener, said first and second rib extensions extending from said second rib portion and being disposed in a plane containing the longitudinal axis of said fastener.  
     
     
       2. The assembly of claim  1  wherein said first and second rib portions are annular and are disposed concentrically. 
     
     
       3. The assembly of claim  1  wherein said first and second rib extensions extend from said second rib portion at diametrically opposed locations, said first rib extension extending toward a first side portion of said cover, said second rib extension extending toward a second side portion of said cover. 
     
     
       4. The assembly of claim  3  wherein, prior to being crushed, said first rib portion is spaced from said head portion of said fastener by a first distance to define a first gap and said second rib portion is spaced from said webbing guide by a second distance to define a second gap, said second distance being less than said first distance. 
     
     
       5. The assembly of claim  4  wherein said first and second rib extensions which extend from said second rib portion are spaced from said webbing guide by said second distance. 
     
     
       6. The assembly of claim  5  wherein, upon impact of a vehicle occupant's head against said cover portion, said second gap closes before said first gap closes so that said second rib portion absorbs a larger portion of the energy of the impact than said first rib portion. 
     
     
       7. The assembly of claim  6  wherein said first and second rib portions are approximately one millimeter thick. 
     
     
       8. The assembly of claim  1  wherein said resilient cover is made of a homogeneous plastic material. 
     
     
       9. An assembly for use in a vehicle, said assembly comprising: 
       a webbing guide for guiding movement of seat belt webbing in the vehicle;  
       a fastener for mounting said webbing guide in position in the vehicle, said fastener including a head portion; and  
       a resilient cover including a cover portion covering said head portion of said fastener and at least a portion of said webbing guide,  
       said resilient cover further including a wall portion extending from the perimeter of said cover portion toward said webbing guide, a first rib portion spaced apart from said wall portion and projecting from said cover portion toward said head portion of said fastener, and a second rib portion spaced apart from said wall portion and said first rib portion and projecting from said cover portion toward said webbing guide,  
       said first rib portion having a circular, hollow shell configuration, said second rib portion having a circular, hollow shell configuration, and said first and second rib portions being disposed concentrically,  
       said first and second rib portions being resiliently crushable to absorb energy in response to an impact of a vehicle occupant's head against said cover portion.  
     
     
       10. The assembly of claim  9  wherein said resilient cover further includes first and second rib extensions which extend from said second rib portion, said rib extensions extending radially from said second rib portion at diametrically opposed locations, said first rib extension extending toward a first side portion of said cover, said second rib extension extending toward a second side portion of said cover. 
     
     
       11. The assembly of claim  9  wherein said resilient cover provides said assembly with an HIC(d) of under 1000 determined in accordance with the United States Department of Transportation Federal Motor Vehicle Safety Standard No. 201 (1996). 
     
     
       12. An assembly for use in a vehicle, said assembly comprising: 
       a webbing guide for guiding movement of seat belt webbing in the vehicle;  
       a fastener for mounting said webbing guide in position in the vehicle, said fastener including a head portion; and  
       a resilient cover including a cover portion covering said head portion of said fastener and at least a portion of said webbing guide,  
       said resilient cover further including a first rib portion projecting from said cover portion toward said head portion of said fastener and a second rib portion projecting from said cover portion toward said webbing guide,  
       said first and second rib portions being resiliently crushable to absorb energy in response to an impact of a vehicle occupant's head against said cover portion, and  
       said resilient cover further including first and second rib extensions which extend from said second rib portion, said rib extensions extending at diametrically opposed locations, said first rib extension extending toward a first side portion of said cover, said second rib extension extending toward a second side portion of said cover.  
     
     
       13. The assembly of claim  12  wherein, prior to being crushed, said first rib portion is spaced from said head portion of said fastener by a first distance to define a first gap and said second rib portion is spaced from said webbing guide by a second distance to define a second gap, said second distance being less than said first distance. 
     
     
       14. The assembly of claim  13  wherein said first and second rib extensions which extend from said second rib portion are spaced from said webbing guide by said second distance. 
     
     
       15. The assembly of claim  14  wherein, upon impact of a vehicle occupant's head against said cover portion, said second gap closes before said first gap closes so that said second rib portion absorbs a larger portion of the energy of the impact than said first rib portion. 
     
     
       16. The assembly of claim  12  wherein said first and second rib portions are approximately one millimeter thick. 
     
     
       17. The assembly of claim  12  wherein said resilient cover is made of a homogeneous plastic material. 
     
     
       18. An assembly for use in a vehicle, said assembly comprising: 
       a webbing guide for guiding movement of seat belt webbing in the vehicle;  
       a fastener for mounting said webbing guide in position in the vehicle, said fastener including a head portion; and  
       a resilient cover including a cover portion covering said head portion of said fastener and at least a portion of said webbing guide,  
       said resilient cover further including a wall portion extending from the perimeter of said cover portion toward said webbing guide, a first rib portion spaced apart from said wall portion and projecting from said cover portion toward an end surface of said head portion of said fastener, and a second rib portion spaced apart from said wall portion and spaced apart from said first rib portion, said second rib portion projecting from said cover portion toward said webbing guide,  
       said first rib portion having a circular, hollow shell configuration, said second rib portion having a continuously curved, hollow shell configuration defining an interior chamber, said first rib portion being located within said interior chamber,  
       said first and second rib portions being resiliently crushable to absorb energy in response to an impact of a vehicle occupant's head against said cover portion.